NOTES: EPA
is no longer estimating lead emissions.
The data presented here appeared in prior year EPA reports.

Revisions to previous estimates are all
related to the development of the 1999 National Emissions Inventory
(NEI). The 1999 estimates in the table
are taken from Version 2 of the 1999 NEI and reflect many new data submissions
from state and local air management agencies.
The 1999 emissions estimates from mobile sources are in most cases
based on the new MOBILE6 and the draft NONROAD2002 emissions models. This is the first time that estimates using
these models have appeared in this format.
Some but relatively few mobile source estimates were provided by state
air agencies. The largest set of
state-submitted data in 1999 was from California. Estimates for mobile sources for years
prior to 1999 were made consistent with the estimates for 1999 and later,
allowing for a generally consistent time trend except that state-submitted
data was incorporated for 1999
only.